Sub-interval timer



Sept. 16, 1969 J. BOWMAN SUB-INTERVAL TIMER Filed Nov. 7, 1966 States Patent 3,467,795 SUB-INTERVAL TIMER Joe Bowman, Greentown, Ind., assignor, by m'esne assignments, to The Scott & Fetzer Company, Lakewood,

Ohio, a corporation of Ohio Filed Nov. 7, 1966, Ser, No. 592,431 Int. Cl. H0111 7/08 US. Cl. 20038 8 Claims ABSTRACT OF THE DISCLOSURE A sequential timer of the step-by-step type has, in addition to conventional components, a continuously rotatably driven member having a cam track and an auxiliary switch controlled thereby to be actuated between increments of movement of the main timing cam. The continuously rotatably driven member can close the auxiliary switch more than once for each step that the main cam is driven by the step-by-step mechanism. The auxiliary switch is supported on a cover that encloses the step-bystep mechanism, there being structural details by which the auxiliary switch structure is automatically aligned with the step-by-step mechanism during assembly of the device.

This invention relates generally to an electrical sequence timer of the stepby-step type, and more specifically to one such timer having a sub-interval switch.

Sequence timers are employed in home appliances, such as in electric washing wachines, to control and to render automatic the many circuits embodied therein. As the complexity of the control circuits has increased, the number of switches required in the sequence timer of such appliance has also increased. Washing machine manufacturers have thus asked for sequence timers having more circuits than those then commercially available. When such timer comprises molded parts as for the housing and the main timing cam, the addition of but one electrical switch may thus entail complete retooling of the device, coupled with an attendant cost increase to the public, the size of which increase is out of all proportion to the benefit that would be provided. Certain appliance manufacturers have circuits that require the closing and opening of a circuit for a few seconds, such duration being less than the duration of each increment of movement of the main timing cam.

Accordingly, it is an object of the present invention to provide an improved construction for a sequence timer.

A further object of the present invention is to provide an electrical sequence timer of the step-by-step type wherein a further switch is actuated at sub-intervals of such steps.

Yet another object of the present invention is to provide an electrical sequence timer with an auxiliary switch which may be embodied therein as a modification without retooling of major timer components.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying drawing sheet in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

On the drawings:

FIG. 1 is a side view of a sub-interval timer provided in accordance with the principles of the present invention; and

FIG. 2 is an end view thereof.

As shown on the drawings:

The principles of this invention are particularly useful when embodied in an electrical sequence timer such as illustrated in FIG. 1, generally indicated by the numeral 10. The timer 10 includes a housing 11, a motor-driven step-by-step mechanism generally indicated by the numeral 12, at least a portion of which is enclosed by a cover 13. Within the housing 11, there is provided a conventional sequence cam 41 which is rotatably supported by the housing 11, the sequence cam having a series of conventional tracks such as 42 thereon. Coacting with such tracks, there is provided a series of electrical switches (not shown) in the housing 11 and disposed to be respectively actuated by the tracks. The structure described in this paragraph is shown in detail in US. Patent No. 3,071,017, to which any interested reader is referred for additional details.

As shown and described in Patent No. 3,071,017, the motor-driven step-by-step mechanism 12 includes a motor 14 which has an output pinion 15 drivably connected to a continuously rotatable drive member 16 which has a stepping cam track 17 engaged by a lever arm 18. A spring 19 acts through a ratchet lever 20 to bias the lever arm 18- against the stepping cam track 17, which acts against the force of such spring 19 to rock the ratchet lever 20 for indexing the main sequence cam 42.

In accordance with the present invention, the continuously rotatable driven member 16 is provided with a further cam track 21, 21, and the cover 13 is provided with an insulative sheet 22 secured to and supported thereby on the outside thereof.

A further switch 23 is supported by the insulative sheet 22 on the outside thereof, remote from the sequence cam within the housing 11, and adjacent to the step-bystep mechanism 12. The further switch 23 includes a cam follower blade 24 and a stationary blade 25.

The mechanism 12 includes a pin 26 which, as best seen in FIG. 2, is riveted at its lower end to a plate 27 secured to the housing 11. The pin provides the support for the continuously rotatable driven member 16, and the outer end of the pin 26 is received in a notch or aperture in the cover 13 so as to align the follower blade 24 with the cam track 21, 21. In this embodiment, the cam track 21, 21 has two lobes so that for each revolution of the cam track, the sub-interval or further switch 23 opens and closes twice for each actuation of the main sequence cam by the stepping mechanism 12. The follower blade 24 is provided with a terminal 28 which with the blade 24 is secured to the insulative sheet 22 by a rivet 29. Similarly, the switch blade 25 is provided with a terminal 30 and a rivet 31 which secures such terminal 30 and the blade 25 to the insulative sheet 22. The blades 24, 25 are provided with a pair of coacting contacts 32. As shown in FIG. 1, the metallic cover has an aperture 33 which insulates the rivet 29 from the cover 13, and a further irregular aperture 34 by which the rivet 31, the contact blade 25, and the follower portion of the blade 24 are insulated from the cover 13. Within the irregular aperture 34, and circumscribed thereby, the insulative sheet has a notched aperture 35. The contact blade 25 has its contact portion offset into the aperture 35 which includes a notch 36 that receives and locates the offset portion of the shorter blade 25.

To enclose the auxiliary or further switch 23, an additional or auxiliary cover 37 is disposed on the outside of the insulative sheet 22 and is secured by three rivets 38, which also hold the insulative sheet 22 onto the cover 13.

In this embodiment, the rotatable member 16 makes one revolution to effect each incremental advance of the main sequence cam. Thus each of the basic increments has a duration corresponding to one revolution of the rotatable member 16. However, as the cam track 21 thereof has two rises and two falls, the further switch 23 is opened and closed within such interval, and in this embodiment is opened and closed twice within such interval, whereby the further switch 23 operates at sub-intervals or at points other than when an actuation of the other switches is taking place.

The cover 13 is held in position by a number of bendable ears 39, 40.

Although various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted herein all such embodiments as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. A sequence timer, comprising in combination:

(a) a housing;

(b) a sequence cam rotatably supported in said housing and having a series of tracks thereon;

(c) a series of electrical switches in said housing and disposed to be respectively actuated by said tracks;

(d) a motor-driven mechanism secured to said housing for periodically rotating said sequence cam in increments in a step-by-step manner, said mechanism including a continuously rotatably driven member having a cam track; and

(e) a further switch disposed in a position remote from said sequence cam and adjacent to said stepby-step mechanism, said further switch having a cam follower blade responsive to said cam track of said member for being actuated between increments of movement of said sequence cam.

2. A sequence timer according to claim 1, in which said cam track of said member has a profile which closes said further switch more than once for each step that said sequence cam is incrementally rotated. I

3. A sequence timer according to claim 1, including a cover enclosing at least a portion of said motor-driven mechanism which includes said continuously rotatably driven member, said cover supporting said further switch in a position adjacent to said continuously rotatably driven member.

4. A sequence timer according to claim 3, in which said cover is metallic, there being an insulative sheet secured thereto to which said further switch is attached, said cover being apertured at the terminals and contacts of said further switch to be insulated therefrom.

5. A sequence timer according to claim 4 in which said insulative sheet is secured to the outside of said cover and said further switch is disposed on the outer side of said insulative sheet, and an auxiliary cover on the outside of said insulative sheet enclosing said further switch.

6. A sequence timer according to claim 3, including a pin projecting from said housing on which pin said rotatably driven member is supported, said pin extending into said cover by which said cam follower blade is aligned with said cam track of said member.

7. A sequence timer according to claim 4, in which said insulative sheet has a notched aperture circumscribed by one of the cover apertures, said further switch including a stationary blade having an ofiset extending into and located by said notched aperture.

8. A sequence timer according to claim 7,

(a) said cam track of said member having a profile closing said further switch more than once for each step that said sequence cam is incrementally rotated; I

(b) said insulative sheet being secured to the outside of said cover and said further switch being disposed on the outer side of said insulative sheet;

(0) an auxiliary cover on the outside of said insulative sheet enclosing said further switch; and

(d) a pin projecting from said housing on which pin said rotatably driven member is supported, said pin extending into said cover by which said cam follower blade is aligned with said cam track of said member.

10/1967 Dotto. 3/1968 Dotto.

H. O. JONES, Primary Examiner 

